Not sure if it is price in already as the stock has been trading down at this level for a while. My guess is that the market is waiting to see if it does get approved, which it sounds like it will, and what the pricing will be on the drug to see if it will be competitive in the HEP C market. The CEO said he feels confident they will be competitive so my guess is the pricing will be to the market's liking.
They should just sell to Google assuming Google would even want them. Google is run much better, obviously, and could probably turn Twitter into a much better platform. Plus, it would help them compete with Facebook in online advertising.